Intravenous (IV) administration sets which are useful for infusing medical fluids to a patient are well known and widely used. In the most simple configuration, an IV administration set includes a fluid source, an IV line connecting the fluid source to the patient, and a medical device operatively associated with the IV line to influence the rate of fluid flow to the patient. Not surprisingly, several medical devices have been proposed for this purpose.
Typically, medical devices which are used in IV administration sets are generally categorized as either pumps or controllers. The difference between the two being that controllers rely on gravity for the flow of fluid through the set, while pumps exert a mechanical force on the fluid to establish a fluid flow. Within the pump category, several different types can be identified. For example, one type of pump which is frequently used in an IV administration set is a volumetric pump. A volumetric pump incorporates a valved fluid chamber in combination with a reciprocal piston such as is disclosed in U.S. Pat. No. 3,985,133 which is assigned to the same assignee as the present invention. Another type of pump which can be used in an IV administration set is a peristaltic pump. Quite different from the volumetric pump, the peristaltic pump creates a moving zone of occlusion along the IV line and uses this action to pump fluid through the administration set. An example of this type pump is disclosed in U.S. Pat. No. 4,617,014 which is also assigned to the same assignee as the present invention. Further, there are mechanisms which do not act in association with the IV line between the fluid source and the patient. Instead, mechanisms of this type act directly on the fluid source to pump fluid from the source and through the set to the patient. Such a mechanism is disclosed in U.S. Pat. No. 4,544,369 and is an example of the familiar syringe pump. Still another type device for administering medical fluids to a patient incorporates both the fluid source and the pumping mechanism into a self-contained combination. As an example, such a device can rely on the contraction of an elastomeric membrane to provide the forces necessary to pump fluid from the device. A device of this type is disclosed in U.S. Pat. No. 4,968,301 which is assigned to the same assignee as the present invention. It is a device of this latter type that is of importance for the present invention.
With advancements in medicine, and the development of complex medical procedures and protocols to implement these advancements, there has been increased reliance on infusion therapy for the care and maintenance of patients. Not infrequently, infusion therapy requires the concerted administration of several fluid medicaments in a prescribed timed sequence. To do this, IV administration set systems that incorporate multiple fluid sources and multiple pumping mechanisms need to be assembled. Unfortunately, the assembly and implementation of such a system is inherently complex and somewhat cumbersome. Consequently, the more simple the system can be, the better.
One simplification for a multiple medicament IV infusion system is to use fewer components. Thus, a self-contained device which combines both the fluid source and the pumping mechanism in a single unit may be preferred. A single unit which uses an elastomeric membrane for its pumping mechanism also has other benefits. The fact such a device is not electrically operated, and the fact it can be pre-loaded with a predetermined amount of fluid medicament, both simplify its use. Further, the pumping mechanism itself has no power requirements and needs no complicated electrical hook-up. A single such device, however, can not implement a multiple medication protocol. Accordingly, there is a need for a system which coordinates the concerted use of multiple pumps of this type.
In light of the above it is an object of the present invention to provide a multiple medicament system for infusing IV fluids to a patient which uses a plurality of self-contained units that each have their own fluid source and pumping mechanism. Another object of the present invention is to provide a multiple medicament system for infusing IV fluids to a patient which coordinates the time duration and sequencing for infusion of a plurality of independent IV administration sets. Still another object of the present invention is to provide a multiple medicament system for infusing IV fluids to a patient which is modular in order to accommodate different numbers of IV administration sets. Yet another object of the present invention is to provide a multiple medicament system for infusing IV fluids to a patient which is simple to use, relatively easy to manufacture and comparatively cost effective.